The largest Spanish-language newspaper in Massachusetts is endorsing US Representative Edward J. Markey over Gabriel E. Gomez in the US Senate race, saying Markey’s stance on the issues should override any desire to catapult the first Latino senator from the state into office.

El Planeta, a Somerville-based newspaper with a circulation of 40,000, said it endorsed Markey because the Irish-American Democrat would fight harder “to continue opening doors” for Latinos than Gomez, the son of Colombian immigrants and the Republican nominee.

“You would expect that for a Spanish-language media outlet, during an electoral campaign with a Latino US Senate candidate, the decision to support him would be easy,” the three-person editorial board wrote in an endorsement to be published Friday. But, they added, “on the matters that most affect the Latino community in Massachusetts, we think that Edward Markey has demonstrated a greater commitment to the defense of those issues than the Republican candidate, Gabriel Gómez.”

The endorsement is the first for the newspaper, founded in 2004, and follows a string of endorsements from prominent Latinos that could sway the Latino electorate in Markey’s favor in the June 25 special election. Latinos are 10 percent of the state’s population but 6 percent of eligible voters; many are too young to vote or are not US citizens.

Still, with nearly 300,000 eligible Latino voters from Boston to Springfield, an increased turnout could make a difference in a race that has narrowed. Both candidates are scrambling to court voters in English and Spanish: Markey has campaigned in ethnic enclaves in Boston and Springfield, home to the largest Latino populations in the state, while Gomez lobbied Latinos last weekend at backyard barbecues and will hold a Latino town hall Saturday in Southbridge.

On Thursday, the Gomez campaign deflected the newspaper’s endorsement of Markey and said Gomez’s story resonates with Latinos. His first language is Spanish, though, like many children of immigrants, he speaks English better. Many immigrants find his success story appealing: He became a Navy SEAL then a businessman with a master’s in business from Harvard.

“Like in any campaign, we will receive some endorsements, and our opponent will receive others,” said Will Ritter, Gomez’s press secretary. “The most important endorsement is the one we get from Latino voters on June 25. We will take nothing for granted in this election.”

‘On the matters that most affect the Latino community in Massachusetts, we think that Edward Markey has demonstrated a greater commitment.’

The Markey campaign said he “is proud to receive the endorsement of El Planeta, which represents the diverse interests, values and voices of the Latino community.”

Chief editor Ana Julia Jatar said an editorial committee that also included publisher Javier Marin and associate editor Rafael Ulloa examined the candidates’ platforms and performance in the debates in deciding whom to endorse. Jatar said Markey granted an interview, while Gomez did not.

The editorial praised Markey for supporting an immigration overhaul “without hesitation,” as well as President Obama’s health care program and funding for education and health care. They also favored Markey’s support for gun control and abortion rights.

“On all those issues, Edward Markey has demonstrated resolve, while the candidate Gabriel Gómez has exhibited erratic postures that suggest, at least, conflicts of identifying with the central agenda of his party,” the newspaper said.

Gomez’s campaign says he supports a path to citizenship for illegal immigrants and expanded background checks for gun buyers, but Jatar and others said his stance has not been clear or strong enough.

For similar reasons, several prominent Latinos have also backed Markey, including Marcos Devers, a state representative from the mostly Latino city of Lawrence, union leader Rocio Saenz, and US Representative Xavier Becerra, a Democrat from California, who campaigned with Markey.

“I congratulate Gomez on his intentions and for being part of the political process as a Latino,” said Devers, an immigrant from the Dominican Republic running for mayor of Lawrence. “But I’m a Latino Democrat. I think he’s on the wrong team.”

Saenz, president of SEIU Local 615, where Latinos are more than half of the 18,000 members, said she supports Markey because of his record of supporting workers, families, and immigrant rights.

“We want to make sure that somebody is going to be out there fighting for the things that we care about,” she said.

El Planeta is distributed free, mainly in Greater Boston. It has a website, tuboston.com.

Julio Ricardo Varela, who runs Latinorebels.com, said he suspects that some Latinos will support Gomez because they identify with him. Varela has chastised the GOP for failing to invest more in Gomez, who could help them reach out to a group they have alienated in the past over issues such as immigration.

“Whether you agree with Gabriel Gomez’s politics or not, what he did being the first Latino to win a statewide primary is an incredible historical accomplishment for Massachusetts,” Varela said.

In fact, eligible Latino voters in Massachusetts are far different from the national Latino electorate, according to the Pew Hispanic Center. Nationwide, a majority of Latinos are of Mexican descent, but in Massachusetts most Latino voters are US citizens of Puerto Rican descent, who might be more preoccupied with the debate over statehood for the Caribbean island than immigration.

The next largest group is Dominicans, who studies show are largely here legally. Other groups include Salvadorans, Guatemalans, and Colombians. Mexicans are about 5 percent.

Stephanie Ebbert contributed to this report. Maria Sacchetti can be reached at msacchetti@globe.com.